Application of Plant Growth-Promoting Bacteria as an Eco-Friendly Strategy for Mitigating the Harmful Effects of Abiotic Stress on Plants

Plant growth-promoting bacteria(PGPB)play an important role in improving agricultural production under several abiotic stress factors.PGPB can be used to increase crop growth and development through hormonal balance and increase nutrient uptake.The positive effect of PGPB may be due to its pivotal role in morphophysiological and biochemical characteristics like leaf number,leaf area,and stem length.Furthermore,relative water content,chlorophyll content,carotenoids,antioxidant enzymes,and plant hormones were improved with PGPB treatment.Crop yield and yield components were also increased with PGPB treatment in numerous crops.The anatomical structure of plant organs was increased such as lamina thickness,stem diameter,xylem vessel diameter,and number of xylem vessels as well as phloem thickness under treatment with PGPB.Additionally,PGPB can alleviate the negative effects of several abiotic stresses by regulating the antioxidant defense system to scavenge the reactive oxygen species resulting in an improvement of yield production in the stressed plants.Additionally,gene expressions were controlled by calcium ion modulation during secondary messengers that act upon calcium-dependent protein kinase and protein phosphatases.This includes many transcription factors such as MYB,AP2/ERF,bZIP,and NAC which regulate genes related to salinity stress signals.PGPB can demonstrate induction genes of signaling under abiotic stress conditions.This review gives an outline of the PGPB role in alleviating the harmful effects of abiotic factors such as salinity,drought,and heat associated with the improvement of the morpho-physiological and biochemical features especially,leaves and branches number,leaf area,antioxidant compounds,plant hormones,and relative water content.

Ecology of Indigenous Plants in Abandoned Agricultural Areas in Tabuk Region, Saudi Arabia

Due to drought, low soil fertility, little rain fall, elevated levels of evapotranspiration, salinization of the soil and a lack of ground water, the problem of desertion of agricultural areas has developed in KSA in recent years (e.g. Tabuk region). In the Saudi Arabia, agricultural land abandonment’s negative impact on the composition of perennial vegetation, soil quality, and the structure of population was investigated. In the several abandoned fields of the research region, eleven species of perennial plants pertaining to nine families, eleven genera were found. Following the use of the ordination of detrended correspondence analysis (DCA), four plant communities were found. Zygophyllum hamiense, Prosopis farcta, Seidlitzia rosmarinus, Traganum nudatum. The indicators were Pulicaria undulate, Calligonum comosum. Populations of Calligonum comosum and Zygophyllum hamiense were found to be either negatively skewed or inversely J-shaped, indicating fast-growing populations with strong reproductive potential, according to demographic research. Traganum nudatum, Prosopis farcta and S. Rosmarinus, on the other hand, have a nearly symmetrical size-frequency distribution (like a bell in shape). The current research highlights the importance of managing deserted agricultural fields in order to restore and improve range lands having adapted native plants to regional conditions like little water demand.